Abstract: The dynamic change characteristic of groundwater radon data from 1986 to 2016 in Fengman seismic station is analyzed and the relationship between its anomalies and seismic activity is studied. The results shows that:the appear and disappear time of the anomalies are related to the middle and strong earthquakes in Northeast China and North China and the strong earthquakes activity in the north part of the western Pacific earthquake zone etc. Its earthquake reflection effect is better, which may provide reference for earthquake forcasting using groundwater radon anomalies in Fengman seismic station.